Expandable, adjustable inter-body fusion devices and methods

ABSTRACT

An expandable, adjustable inter-body fusion device is presented. The inter-body fusion device can have a first plate, a second plate, and an insert positioned substantially therebetween the first plate and the second plate. The first plate, the second plate, and the insert define an interior cavity. Moving the insert longitudinally with respect to the first and second plates increases or decreases the distance of the first plate with respect to the second plate, effectively expanding the inter-body fusion device and increasing the volume of the interior cavity. The angle between the first plate and the second plate is selectively adjustable.

RELATED APPLICATIONS

This application is a continuation of co-pending U.S. Ser. No.16/806,243 filed on Mar. 2, 2020 which is a continuation of co-pendingU.S. Ser. No. 16/708,209 filed on Dec. 9, 2019 entitled “Expandable,Adjustable Inter-Body Fusion Devices And Methods”, which is acontinuation of U.S. Ser. No. 16/210,240 filed on Dec. 5, 2018 now U.S.Pat. No. 10,500,064 issued on Dec. 10, 2019 which is a continuation ofU.S. Ser. No. 15/521,995 filed on Apr. 26, 2017 now U.S. Pat. No.10,285,824 issued on May 15, 2019 which is a national stage entry ofPCT/US2015/057892 filed on Oct. 28, 2015 claiming priority to U.S.provisional application 62/069,362 filed on Oct. 28, 2014; andco-pending U.S. Ser. No. 16/806,243 filed on Mar. 2, 2020 is acontinuation of co-pending U.S. Ser. No. 15/549,169 entitled“Expandable, Adjustable Inter-Body Fusion Devices And Methods”, which isa national stage entry of PCT/US16/16899 filed on Feb. 5, 2016 claimingpriority to U.S. provisional application 62/112,332 filed on Feb. 5,2015.

FIELD OF THE INVENTION

This invention relates generally to spinal surgery, and moreparticularly to devices and methods for stabilization of the spine inassociation with placement of an expandable inter-body construct with anadjustable construct angle for inter-body fusion or the like.

BACKGROUND OF THE INVENTION

Damage or disease that affects the spinal disc within an individual'sspinal column may lead to neurologic impairment with possible permanentdamage to the surrounding tissue. Maintaining proper anatomic spacingand lordosis within the spine is critical to ensuring continuedfunctionality of the surrounding tissue and for the spinal column, thespinal cord and nerve roots and therefore, avoidance of long termserious neurological impairment.

Typically, spinal implants that are used as a spacer type of device havea fixed overall length and are implanted without the ability to adjustthe degree of expansion or curvature without using multiple insertioninstrumentation. Some of the known procedures for introducing spinalimplants comprise Anterior Lumbar Inter-body Fusion (“ALIF”), LateralLumbar Inter-body Fusion (“LLIF”), Posterior Lumbar Inter-body Fusion(“PLIF”), Oblique Lumbar Inter-body Fusion (“OLIF”), Direct LateralFusion (“DLIF”), Transforaminal Lumbar Inter-body Fusion (“TLIF”), andthe like. A need remains for an expandable, adjustable spacer type ofimplant that allows the surgeon to insert the implant in an unexpandedposition to minimize the size of the surgical incision, facilitate theoperative technique and decrease patient morbidity.

SUMMARY OF THE INVENTION

Presented herein is an inter-body fusion device, or implant, for use inspinal surgery. In one aspect, the inter-body fusion device can be anexpandable fusion device having an expandable height and volume. Inanother aspect, the inter-body fusion device can be an adjustable fusiondevice such that an angle formed between an upper bone contact surfaceand a lower bone contact surface is selectively adjustable by thesurgeon.

In one aspect, the inter-body fusion device comprises a first plate, asecond plate, and an insert positioned substantially therebetween thefirst plate and the second plate. The first plate, the second plate, andthe insert define an interior cavity. In one aspect, moving at least aportion of the insert longitudinally with respect to the first andsecond plates in a first direction increases the distance between thefirst plate relative to the second plate, effectively expanding theinter-body fusion device and increasing the volume of the interiorcavity. In another aspect, moving at least a portion of the insertlongitudinally with respect to the first and second plates in the firstdirection increases the angle formed between the first plate relative tothe second plate.

It is contemplated that this technology can be used for a variety ofimplants used for a variety of spinal procedures. These proceduresinclude, but are not limited to OLIF (anterior or posterior), DLIF,PLIF, TLIF, ALIF, and LLIF. So, depending upon the procedure and pointof insertion for the implant, the geometry of the implant can differ.

In an exemplified aspect, at least one of the first plate and the secondplate define at least one graft window that is in communication with theinterior cavity.

Also presented herein is a method of using an inter-body fusion deviceduring an inter-body fusion procedure. In one aspect, the methodcomprises accessing the desired disc space, choosing the correct insertsize with the appropriate height range, inserting the inter-body fusiondevice into the desired area in the disc space, expanding the inter-bodyfusion device from a first unexpanded position to a second expandedposition and adjusting the angle formed between the first plate relativeto the second plate to a desired angle. An additional step of packingthe interior cavity via with bone fusion material either prior to orafter expansion is also contemplated.

Related methods of operation are also provided. Other apparatuses,methods, systems, features, and advantages of the inter-body fusiondevice and the method of its use will be or become apparent to one withskill in the art upon examination of the following figures and detaileddescription. It is intended that all such additional apparatuses,methods, systems, features, and advantages be included within thisdescription, be within the scope of the inter-body fusion device and themethod of its use, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate certain aspects of the instantinvention and together with the description, serve to explain, withoutlimitation, the principles of the invention. Like reference charactersused therein indicate like parts throughout the several drawings.

FIG. 1 is a front perspective view of one embodiment of an expandable,adjustable inter-body fusion device in a second expanded position, thedevice comprising a first plate, a second plate and an insert, accordingto one aspect;

FIG. 2 is a front perspective of the inter-body fusion device of FIG. 1in the second expanded position, in which a device angle between thefirst plate and the second plate is substantially 0 degrees (the firstplate and the second plate are substantially parallel), and in which thefirst plate is illustrated transparently for clarity;

FIG. 3 is a front perspective of the inter-body fusion device of FIG. 1in a first unexpanded position;

FIG. 4 is a front perspective of the inter-body fusion device of FIG. 1in the second expanded position, and in which the device angle betweenthe first plate and the second plate is greater than 0 degrees;

FIG. 5 is front perspective view of the insert of FIG. 1, according toone aspect;

FIG. 6 is a side elevational view of the insert of FIG. 5;

FIG. 7 is a rear perspective view of the insert of FIG. 5;

FIG. 8 is a front perspective of the inter-body fusion device of FIG. 1in the second expanded position, in which the device angle between thefirst plate and the second plate is substantially 0 degrees, and inwhich the first plate is illustrated transparently for clarity, showingthe inter-body fusion device coupled to a device driver, according toone aspect;

FIG. 9 is a front perspective of the inter-body fusion device of FIG. 1in the second expanded position, in which the device angle between thefirst plate and the second plate is greater than 0 degrees, and in whichthe first plate is illustrated transparently for clarity, showing theinter-body fusion device coupled to a device driver, according to oneaspect;

FIG. 10 is a front perspective of the inter-body fusion device of FIG. 1in the first unexpanded position, in which the first plate isillustrated transparently for clarity, showing the inter-body fusiondevice coupled to a device driver, according to one aspect;

FIG. 11 is a rear perspective of the inter-body fusion device of FIG. 1in the first unexpanded position, in which the first plate isillustrated transparently for clarity, showing the inter-body fusiondevice coupled to a device driver, according to one aspect;

FIG. 12 is side elevational of the device driver of FIG. 9, showing thedevice driver coupled to the inter-body fusion device of FIG. 1,according to one aspect;

FIG. 13 is a front perspective view of a second embodiment of anexpandable, adjustable inter-body fusion device in a first unexpandedposition, the device comprising a first plate, a second plate and aninsert, according to one aspect;

FIG. 14 is a perspective view of the inter-body fusion device of FIG. 13in the first unexpanded position, in which the first plate isillustrated transparently for clarity;

FIG. 15 is a perspective view of the inter-body fusion device of FIG. 13in a second expanded position in which the device angle between thefirst plate and the second plate is substantially 0 degrees.

FIG. 16 is a perspective view of the inter-body fusion device of FIG. 13in the second expanded position in which the device angle between thefirst plate and the second plate is substantially 0 degrees and in whichthe first plate is illustrated transparently for clarity;

FIG. 17 is a perspective view of the inter-body fusion device of FIG. 13in the second expanded position and in which the device angle betweenthe first plate and the second plate is greater than 0 degrees;

FIG. 18 is a perspective view of the inter-body fusion device of FIG. 13in the second expanded position, in which the device angle between thefirst plate and the second plate is greater than 0 degrees and in whichthe first plate is illustrated transparently for clarity;

FIG. 19 is a perspective view of the insert of the inter-body fusiondevice of FIG. 13, according to one aspect;

FIG. 20 is a side elevational view of the insert of FIG. 19;

FIG. 21 is a front perspective view of a third embodiment of anexpandable, adjustable inter-body fusion device in a second expandedposition, the device comprising a first plate, a second plate and aninsert, and in which a device angle between the first plate and thesecond plate is substantially 0 degrees, according to one aspect;

FIG. 22 is a perspective view of the inter-body fusion device of FIG. 21in the second expanded position, in which the first plate is illustratedtransparently for clarity;

FIG. 23 is a perspective view of the inter-body fusion device of FIG. 21in a first unexpanded position;

FIG. 24 is a perspective view of the inter-body fusion device of FIG. 21in the first unexpanded position, in which the first plate isillustrated transparently for clarity;

FIG. 25 is a perspective view of the inter-body fusion device of FIG. 21in the second expanded position, in which the device angle between thefirst plate and the second plate is greater than 0 degrees and in whichthe first plate is illustrated transparently for clarity;

FIG. 26 is a front perspective view of the insert of the inter-bodyfusion device of FIG. 21, according to one aspect;

FIG. 27 is a side elevational view of the insert of FIG. 26; and

FIG. 28 is a rear perspective view of the insert of FIG. 26.

DETAILED DESCRIPTION OF THE INVENTION

The present invention can be understood more readily by reference to thefollowing detailed description, examples, and claims, and their previousand following description. Before the present system, devices, and/ormethods are disclosed and described, it is to be understood that thisinvention is not limited to the specific systems, devices, and/ormethods disclosed unless otherwise specified, as such can, of course,vary. It is also to be understood that the terminology used herein isfor the purpose of describing particular aspects only and is notintended to be limiting.

The following description of the invention is provided as an enablingteaching of the invention in its best, currently known aspect. Thoseskilled in the relevant art will recognize that many changes can be madeto the aspects described, while still obtaining the beneficial resultsof the present invention. It will also be apparent that some of thedesired benefits of the present invention can be obtained by selectingsome of the features of the present invention without utilizing otherfeatures. Accordingly, those who work in the art will recognize thatmany modifications and adaptations to the present invention are possibleand can even be desirable in certain circumstances and are a part of thepresent invention. Thus, the following description is provided asillustrative of the principles of the present invention and not inlimitation thereof.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to a “plate” includes aspects having two or moreplates unless the context clearly indicates otherwise.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance may or may not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

Terms used herein, such as “exemplary” or “exemplified,” are not meantto show preference, but rather to explain that the aspect discussedthereafter is merely one example of the aspect presented.

Additionally, as used herein, relative terms, such as “substantially”,“generally”, “approximately”, and the like, are utilized herein torepresent an inherent degree of uncertainty that may be attributed toany quantitative comparison, value, measurement, or otherrepresentation. These terms are also utilized herein to represent thedegree by which a quantitative representation may vary from a statedreference without resulting in a change in the basic function of thesubject matter at issue.

In one aspect, presented herein is an inter-body fusion device for usein spinal surgery, such as, but not limited to, ALIF, OLIF, TLIF, LLIF,PLIF, and DLIF procedures. In another aspect, the inter-body fusiondevice can be an expandable inter-body fusion device such that a heightof the device can be selectively adjusted by a user, such as a surgeon.In a further aspect, the inter-body fusion device can be an adjustablefusion device such that a device angle formed between an upper bonecontact surface and a lower bone contact surface is selectivelyadjustable by the user. In another aspect, the inter-body fusion devicecan be an expandable, adjustable inter-body fusion device having aselectively expandable height and a selectively adjustable device angle.

In one aspect and as illustrated in FIGS. 1-4, the inter-body fusiondevice 10 comprises a first plate 100, a second plate 200, and an insert300 positioned substantially therebetween the first plate 100 and thesecond plate 200. The first plate has a leading edge 102, a trailingedge 104, an upper bone contact surface 110 and an opposed first plateinner surface 120. The second plate 200 has a leading edge 202, atrailing edge 204, a lower bone contact surface 210 and an opposedsecond plate inner surface 220. In one aspect, the first plate 100, thesecond plate 200, and the insert 300 define an interior cavity 15.

The inter-body fusion device 10 has a leading end 20 and a trailing end30. In one aspect, moving the insert 300 longitudinally with respect tothe first plate 100 and the second plate 200 (that is, either toward theleading end 20 or toward the trailing end 30 of the device) can increasethe distance between the first plate relative to the second plate,effectively expanding the inter-body fusion device and increasing thevolume of the interior cavity 15. In another aspect, a device angle α₁formed between a longitudinal axis L₁ of the first plate 100 and alongitudinal axis L₂ of the second plate 200 can be selectively adjustedby a user to vary the volume of the interior cavity and/or betterposition the device 10 in the disc space. For example, the device anglecan be substantially 0 degrees such that the first plate and the secondplate are substantially parallel to each other. In other examples, thedevice angle α₁ can be an acute angle of about 1 degree, 2 degrees, 3degrees, 4 degrees, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9degrees, 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, 15degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45degrees or greater than about 45 degrees.

At least one of the first plate 100 and the second plate 200 has atleast one longitudinal sidewall 130, 230 extending substantially betweenthe respective inner surface 120, 220 and bone contact surface 110, 210.In one aspect, the at least one longitudinal sidewall 130, 230 comprisesa plurality of longitudinal sidewalls. For example, the longitudinalsidewall can comprise two longitudinal sidewalls. In another aspect, thelongitudinal sidewall(s) can be positioned substantially near aperipheral edge 139, 239 of the first and/or second plate.

In one aspect, the longitudinal sidewall 130 of the first plate 100 cancomprise at least one ramp 132 having an inclined surface 134. That is,at least a portion of the inner surface 120 of the first plate can be aninclined surface that is at an acute surface angle α₂ relative to thelongitudinal axis L₁ of the first plate. For example, the surface angleα₂ can be about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12degrees, 13 degrees, 14 degrees, 15 degrees, 20 degrees, 25 degrees, 30degrees, 35 degrees, 40 degrees, 45 degrees or greater than about 45degrees. In another aspect, the longitudinal sidewall of the first plate100 can further comprise at least one substantially flat surface 136that is substantially parallel to the longitudinal axis L₁ of the firstplate. Optionally, the longitudinal sidewall 130 of the first plate 100can comprise an upper flat surface 138, a first inclined surface 140, alower flat surface 142 and a second inclined surface 144. In thisaspect, the upper flat surface and the lower flat surface can be spacedfrom each other a predetermined distance that is less than the height ofthe insert 300. Alternatively, the upper flat surface 138 and the lowerflat surface 142 can be spaced from each other a predetermined distancethat is greater than or equal to the height of the insert. In anotheraspect, the first inclined surface 140 and the second inclined surface144 can be at the same surface angle α₂ relative to the longitudinalaxis L₁ of the first plate 100. Optionally, however, the first inclinedsurface and the second inclined surface can be at a different surfaceangle α₂ relative to the longitudinal axis L₁ of the first plate. Atleast one pin bore 146 can be defined in a portion of the longitudinalsidewall 130.

In one aspect, the longitudinal sidewall 230 of the second plate 200 cancomprise at least one ramp 232 having an inclined surface 234. That is,at least a portion of the second plate inner surface 220 can be aninclined surface that is at an acute surface angle α₃ relative to thelongitudinal axis L₂ of the second plate. For example, the surface angleα₃ can be about 1 degree, 2 degrees, 3 degrees, 4 degrees, 5 degrees, 6degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12degrees, 13 degrees, 14 degrees, 15 degrees, 20 degrees, 25 degrees, 30degrees, 35 degrees, 40 degrees, 45 degrees or greater than about 45degrees. In another aspect, the longitudinal sidewall of the secondplate 200 can further comprise at least one substantially flat surface236 that is substantially parallel to the longitudinal axis L₂ of thesecond plate. Optionally, the longitudinal sidewall 230 of the secondplate 200 can comprise a lower flat surface 238, a first inclinedsurface 240, an upper flat surface 242 and a second inclined surface244. In this aspect, the upper flat surface and the lower flat surfacecan be spaced from each other a predetermined distance that is less thanthe height of the insert 300. Alternatively, the upper flat surface 242and the lower flat surface 238 can be spaced from each other apredetermined distance that is greater than or equal to the height ofthe insert. In another aspect, the first inclined surface 240 and thesecond inclined surface 244 can be at the same surface angle α₃ relativeto the longitudinal axis L₂ of the second plate 200. Optionally,however, the first inclined surface and the second inclined surface canbe at a different surface angle α₃ relative to the longitudinal axis L₂of the second plate. At least one pin bore 246 can be defined in aportion of the longitudinal sidewall 230.

Referring now to FIGS. 5-7, in one exemplified aspect, the insert 300comprises a first member 302 and a second member 304. In one aspect, thefirst member can be spaced from the second member a predetermineddistance. In another aspect, the first member 302 can be physicallyseparate from the second member 304, as in FIG. 5. Optionally, a portionof the first member can be coupled to the second member (as illustratedin FIGS. 19 and 26).

In one aspect, the first member 302 has a leading edge 306, a trailingedge 308, a first plate contact surface 310 extending between theleading edge and the trailing edge, and an opposed second plate contactsurface 312 extending between the leading edge 306 and the trailing edge308. At least one longitudinal sidewall 314 can extend substantiallybetween the first plate contact surface and the opposed second platecontact surface. A first bore 316 can be defined in a portion of thetrailing edge of the first member. In another aspect, at least a portionof the first bore can be threaded.

The first member 302 can comprise a first threaded shaft 318 and anoptional first retainer 320, according to one aspect. The first retainercan be configured to couple a portion of the first member 302 to atleast one of the first plate 100 and the second plate 200. In anotheraspect, the first threaded shaft can be coupled to a portion of thefirst retainer and can be configured to complementarily engage a portionof the first bore 316. Thus, rotation of the first threaded shaft 318can cause the distance between the trailing edge 308 of the first member302 and the first retainer to change. For example, rotation of the firstthreaded shaft in a first direction can make the distance between thetrailing edge of the first member and the first retainer 320 smaller. Inanother example, rotation of the first threaded shaft 318 in a seconddirection that is opposed to the first direction can make the distancebetween the trailing edge 308 of the first member 302 and the firstretainer 320 larger. A distal end 319 of the first threaded shaft can beconfigured to engage an actuation device, such as a screwdriver and thelike so that rotation of the actuation device can rotate the firstthreaded shaft 318. For example, the distal end of the first threadedshaft can be slotted to engage a regular screwdriver. In anotherexample, the distal end 319 of the first threaded shaft can be shaped toengage a hexagonal driver, and the like.

In one aspect, the second member 304 has a leading edge 322, a trailingedge 324, a first plate contact surface 326 extending between theleading edge and the trailing edge and an opposed second plate contactsurface 328 extending between the leading edge 322 and the trailing edge324. At least one longitudinal sidewall 330 can extend substantiallybetween the first plate contact surface and the opposed second platecontact surface. A second bore 332 can extend through the second memberfrom the leading edge to the trailing edge of the second member. Inanother aspect, the second bore can define a longitudinal pathway 334,and at least a portion of the second bore can be threaded. For example,the second bore 332 can extend longitudinally through the second member304, and a portion or all of the second bore can be threaded.

The second member 304 can comprise a second threaded shaft 336 and anoptional second retainer 338, according to one aspect. The secondretainer can be configured to couple a portion of the second member 304to at least one of the first plate 100 and the second plate 200. Inanother aspect, the second threaded shaft can be coupled to a portion ofthe second retainer and configured to complementarily engage a portionof the second bore 332. Thus, rotation of the second threaded shaft 336can cause the distance between the trailing edge 324 of the secondmember 304 and the second retainer to change. For example, rotation ofthe second threaded shaft in a first direction can make the distancebetween the trailing edge of the second member and the second retainer338 smaller. In another example, rotation of the second threaded shaft336 in a second direction that is opposed to the first direction canmake the distance between the trailing edge 324 of the second member 304and the second retainer 338 larger. A distal end 337 of the secondthreaded shaft can be configured to engage an actuation device, such asa screwdriver and the like so that rotation of the actuation device canrotate the second threaded shaft 336. For example, the distal end of thesecond threaded shaft can be slotted to engage a regular screwdriver. Inanother example, the distal end 337 can be shaped to engage a hexagonaldriver, and the like. In one aspect, a longitudinal duct 339 can bedefined therethrough the second threaded shaft. In use, the longitudinalduct of the second threaded shaft can be substantially coaxially alignedwith the longitudinal pathway 334 of the second member so that at leasta portion of the actuation device can be inserted through both thelongitudinal duct 339 of the second threaded shaft 336 and thelongitudinal pathway 334 of the second member 304. A shoulder 346 of thesecond threaded shaft can engage a portion of the second retainer 338 torestrict longitudinal movement of the second threaded shaft 336.

In one aspect, portions of the first plate contact surfaces 310, 326 ofthe first member 302 and/or the second member 304 can be configured toengage the inner surface 120 of first plate 100 of the device 10. Inanother aspect, portions of the second plate contact surfaces 312, 328of the first member 302 and/or the second member 304 can be configuredto engage the inner surface 220 of the second plate 200. For example,portions of the first plate contact surface 310 of the first member canbe configured to engage the upper flat surface 138 and/or the firstinclined surface 140 of the first plate, and portions of the first platecontact surface 326 of the second member 304 can be configured to engagethe upper flat surface 138 and/or the second inclined surface 144 of thefirst plate 100. In another example, portions of the second platecontact surface 312 of the first member 302 can be configured to engagethe lower flat surface 238 and/or the first inclined surface 240 of thesecond plate 200, and portions of the second plate contact surface 328of the second member 304 can be configured to engage the lower flatsurface 238 and/or the second inclined surface 244 of the second plate.As seen in the FIGS. 1-4, the inclined surfaces of the first and secondplates can cooperate with the flat surfaces 136, 236 to cam or wedge thefirst plate 100 and/or the second plate 200 to a desired position andorientation relative to each other based on the position of the firstmember 302 and the second member 304 relative to the plates.

The inter-body fusion device 10 can further comprise at least one pin400 configured to couple a portion of the insert 300 to at least one ofthe first plate 100 and the second plate 200. For example and asillustrated in FIGS. 1-4, a proximal end 402 of each pin can be formedwith or securedly attached to the pin bore 146 of the longitudinalsidewall 130 of the first plate and/or the pin bore 246 of thelongitudinal sidewall 230 of the second plate such that a distal end 404of the pin 400 extends from the sidewall into the interior cavity 15 ofthe device 10. In one aspect, at least one pin can be positioned suchthat a longitudinal axis L₄ of the pin is substantially transverse tothe longitudinal axis of the first plate L₁. In one aspect, the distalend of each pin can be configured to slidingly engage a first slot 340defined in the first retainer 320 and/or a second slot 342 defined inthe second retainer 338 of the insert 300. In another aspect, the firstslot and/or the second slot can be substantially transverse to alongitudinal axis L₃ of the insert. Optionally, however, the first slot340 and/or the second slot 342 can be at an acute angle relative to thelongitudinal axis L₃ of the insert.

To assemble the inter-body fusion device 10, the insert 300 can bepositioned between the first plate 100 and the second plate 200 suchthat the leading edge 306 of the insert, the leading edge 102 of thefirst plate, and the leading edge 202 of the second plate are facing thesame direction. In one aspect, portions of the first plate 100 canoverlie the second plate 200. Correspondingly, in one aspect, eachlongitudinal sidewall 130 of the first plate 100 can substantially alignwith a longitudinal sidewall 230 of the second plate 200. For example,each longitudinal sidewall of the first plate can substantially overlieat least a portion of a longitudinal sidewall of the second plate.Optionally, each longitudinal sidewall 130 of the first plate 100 can bepositioned adjacent to at least a portion of a longitudinal sidewall 230of the second plate 200 so that the inner surface 120 of the first plateand the inner surface 220 of the second plate do not contact each other.The proximal end 402 of the at least one pin 400 can be coupled to thelongitudinal sidewall of at least one of the first and second plate andthe distal end 404 of the pin can extend into the first slot 340 or thesecond slot 342 of the insert 300. Thus, when assembled, a portion ofpin can slide in the slot and allow the first plate 100, the secondplate 200, and/or the insert to move relative to each other in thedirection of the slot.

Each set of substantially aligned longitudinal sidewalls (a longitudinalsidewall 130 from the first plate 100 and a longitudinal sidewall 230from the second plate 200) define at least one void 160, as illustratedin FIGS. 1 and 2. In another aspect, the at least one void can be sizedand shaped to complimentarily accept a portion of the first member 302or the second member 304 of the insert 300 therein. In this aspect, in afirst unexpanded position (as illustrated in FIG. 3), each of the firstmember and the second member of the insert 300 can be positionedsubstantially within the void 160 formed between the substantiallyaligned longitudinal sidewalls 130, 230 of the first and second plates100, 200. In the first unexpanded position, at least one of the firstmember 302 and the second member 304 can be positioned in the voidsubstantially near or in contact with the respective flat surface 136,236 of the first and second plates. Note that the first unexpandedposition is the position in which the inter-body fusion device 10 can beinserted between the adjacent vertebrae of a patient.

The inter-body fusion device 10 can be selectively expanded about andbetween the first unexpanded position, in which a portion of the firstmember 302 and/or the second member 304 of the insert 300 can bepositioned substantially near or in contact with the respective flatsurface 136, 236 of the first and second plates, and a second expandedposition in which a portion of the first member 302 and/or the secondmember 304 of the insert 300 can be positioned substantially near or incontact with the respective inclined surface 134, 234 of the first andsecond plates 100, 200. That is, in the second expanded position, thefirst member and/or the second member can be spaced from the respectiveflat surface 136, 236 of the first and second plates a predetermineddistance. As can be appreciated, in the second expanded position, theinter-body fusion device 10 can have a height and interior cavity 15volume that is greater than the height and interior cavity volume of theinter-body fusion device in the first, unexpanded position. Thus, in thefirst unexpanded position, the interior cavity 15 of the device can havea first cavity size, and in the second expanded position the interiorcavity can have a second cavity size that is greater than the firstcavity size.

In one aspect, in the first, unexpanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other. Inanother aspect, in the second, expanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other.

In order to selectively expand the inter-body fusion device 10 about andbetween the first unexpanded position and the second expanded position,at least the one of the first member 302 or the second member 304 of theinsert 300 can be moved longitudinally about and between a first insertposition and a second insert position. In one aspect, in the firstinsert position, the trailing edge 308 of the first member can be spacedfrom the trailing edge 104 of the first plate 100 an unexpanded firstdistance, and the trailing edge 324 of the second member can be spacedfrom the trailing edge 104 of the first plate 100 an unexpanded seconddistance. In the second insert position, the trailing edge 308 of thefirst member can be spaced from the trailing edge 104 of the first plate100 an expanded first distance that is less than the unexpanded firstdistance, and the trailing edge 324 of the second member can be spacedfrom the trailing edge 104 of the first plate 100 an expanded seconddistance that is less than the unexpanded second distance.

In moving the inter-body fusion device 10 about and between the firstunexpanded position and the second expanded position, the first member302 and the second member 304 of the insert 300 do not necessarily needbe moved simultaneously or to the same insert position. For example, thefirst member can be in the first insert position while the second membercan be in the second insert position. In another example, the firstmember 302 can be in the second insert position while the second member304 can be in the first insert position. Thus, the first member and thesecond member can be in any insert position between the first insertposition and the second insert position at any time regardless of theposition of the other member.

Upon moving the first member 302 towards the second insert position, atleast a portion of the first plate contact surface 310 can be moved intocontact with the first inclined surface 140 of the longitudinal sidewall130 of the first plate 100, and at least a portion of the second platecontact surface 312 can be moved into contact with the first inclinedsurface 240 of the longitudinal sidewall 230 of the second plate 200. Inthis position, the aligned longitudinal sidewalls of the first andsecond plates 100, 200 are separated by the first member traveling overthe inclined surfaces 140, 240 to cam the plates away from each other.

Similarly, upon moving the second member 304 towards the second insertposition, at least a portion of the first plate contact surface 326 canbe moved into contact with the second inclined surface 144 of thelongitudinal sidewall 130 of the first plate 100, and at least a portionof the second plate contact surface 328 can be moved into contact withthe second inclined surface 244 of the longitudinal sidewall 230 of thesecond plate 200. In this position, the aligned longitudinal sidewallsof the first and second plates 100, 200 are separated by the secondmember traveling over the inclined surfaces 144, 244 to cam the platesaway from each other.

As one skilled in the art can appreciate, the amount of separationachievable between the first plate 100 and the second plate 200 can bedetermined by the height of the inclined surfaces and the distance oflongitudinal movement of the second member. Further, the angle formedbetween the first plate and the second plate can be determined by atleast the position of the first member 302 of the insert relative to thesecond member 304.

It is contemplated that this technology can be used for a variety ofimplants used for a variety of spinal procedures. As mentioned before,these procedures include, but are not limited to OLIF, DLIF, PLIF, ALIF,TLIF, and LLIF. Because of this, depending upon the procedure and pointof insertion for the implant, the geometry of the implant can differ.For example, in a DLIF expandable device, the approach is lateral. Assuch, the upper bone contact surface 110 can be transversely angled withrespect to the lower bone contact surface 210 from a first sidewall to asecond sidewall to match, increase, or decrease lordosis.

In an OLIF procedure, the inter-body fusion device 10 can be insertedobliquely, either anteriorly or posteriorly. As such, similar to theDLIF implant, the upper bone contact surface 110 can be angledtransversely with respect to the lower bone contact surface 210 from thefirst sidewall to the second sidewall depending on the need to match,increase, or decrease lordosis. In addition, the upper bone contactsurface can also be angled longitudinally with respect to the lower bonecontact surface from the leading end 20 of the device to the trailingend 30.

In an exemplified aspect, at least one of the first plate 100 and thesecond plate 200 can define at least one graft window 170, 270 that isin communication with the interior cavity 15. The at least one graftwindow 170 defined in the first plate can overlie at least a portion ofthe at least one graft window 270 of the second plate, therebypermitting bone growth therethrough. In another aspect, the upper bonecontact surface 110 of the first plate 100 comprises ridges 112 forfrictionally engaging a first vertebra of the patient. As can beappreciated, the lower bone contact surface 210 of the second plate cancomprise ridges 212 to frictionally engage a second vertebra of thepatient.

In one aspect, as shown in FIGS. 8-12, the inter-body fusion device 10can be actuated by a device driver 500. The device driver can comprise afirst member driver 502 sized and shaped to engage the distal end 319 ofthe first threaded shaft 318, and a second member driver 504 sized andshaped to engage the distal end 337 of the second threaded shaft 336. Inanother aspect, the first member driver can be a separate tool than thesecond member driver. Optionally, however, the first member driver 502and the second member driver 504 can be integrally formed as illustratedin FIG. 12. For example, the device driver 500 can further comprise ahandle 506 and a clutch collar 508 that allows the device driver to beadjustable between an engaged position and a disengaged position. In theengaged position, the clutch collar can couple the first member driver502 to the second member driver 504 so that, upon rotation of thehandle, both the first member driver and the second member driver rotateat the same speed as the handle. In the disengaged position, the clutchcollar 508 can disengage the first member driver 502 from the secondmember driver 504 so that upon rotation of the handle 506, either thefirst member driver or the second member driver can rotate at the samespeed as the handle while the disengaged driver does not rotate.

In use, the first member driver 502 can be inserted through thelongitudinal duct 339 of the second threaded shaft 336 and through thelongitudinal pathway 334 of the second member 304 so that the firstmember driver can be coupled to the distal end 319 of the first threadedshaft 318 of the first member. The second member driver can be coupledto the distal end 337 of the second member. A gripping element 510 ofthe device driver can grip at least a portion of the inter-body fusiondevice 10, such as, the first plate 100, the second plate, or asillustrated in the figures, the second retainer 338 of the insert 300.The clutch collar 508 of the device driver can be placed in the engagedposition, and the handle 506 of the device driver can be rotated. Forexample, if the inter-body fusion device is in the first, unexpandedposition, rotation of the handle can cause the first member 302 and thesecond member 304 of the insert to move from the first insert positiontowards the second insert position. As the first member and the secondmember move towards the second insert position, the first plate 100 andthe second plate 200 are urged away from each other, and the height ofthe device increases. In another example, if the inter-body fusiondevice is in the second expanded position, rotation of the handle cancause the first member 302 and the second member 304 of the insert tomove from the second insert position towards the first insert position.As the first member and the second member move towards the first insertposition, the first plate 100 and the second plate 200 are can movetowards each other, and the height of the device decreases.

When the desired device height has been reached, the clutch collar canbe moved to the disengaged position. In the disengaged position,rotation of the handle can cause only one of the first member 302 andthe second member 304 to move. For example, rotation of the handle in afirst direction can cause the first member 302 to move longitudinallytowards the trailing edge 104 of the first plate, thereby increasing theangle between the longitudinal axis of the first plate and the secondplate (the device angle). In another example, rotation of the firstmember driver 502 in a second direction that is opposed to the firstdirection can cause the first member 302 to move longitudinally towardsthe leading edge 102 of the first plate 100, thereby decreasing thedevice angle. When the desired device angle has been reached, the devicedriver 500 can be removed from the device 10.

A second embodiment of the inter-body fusion device 10 is illustrated inFIGS. 13-20, according to one aspect. In this embodiment, the inter-bodyfusion device can be as described above, comprising a first plate 100, asecond plate 200, and an insert 300. Optionally, however, the insert canbe a continuous insert. That is, a portion of the first member 302 ofthe insert 300 can be coupled to the second member 304 as illustrated inFIG. 19. In one aspect, the first threaded shaft 318 of the first membercan be configured to matingly engage a portion of the second bore 332 ofthe second member such that rotation of the first threaded shaft canmove the first member 302 longitudinally relative to the second member304. Thus, rotation of the first threaded shaft 318 can cause thedistance between the trailing edge 308 of the first member and theleading edge 322 of the second member to change. For example, rotationof the first threaded shaft in a first direction can make the distancebetween the trailing edge of the first member 302 and the leading edgeof the second member 304 smaller. In another example, rotation of thefirst threaded shaft 318 in a second direction that is opposed to thefirst direction can make the distance between the trailing edge 308 ofthe first member and the leading edge of the second member 304 larger.

Referring still to FIG. 19, a notch 344 can be defined in a portion ofthe first member 302, such as, for example, in the first plate contactsurface 310 and/or the second plate contact surface 312. In one aspect,the notch can be in communication with the first bore 316 so that thefirst threaded shaft 318 can be inserted through the notch and into thefirst bore in a direction from the leading edge 306 to the trailing edge308 of the first member. In another aspect, the first threaded shaft canbe inserted through the notch and through the first bore so that atleast a portion of the distal end 319 of the first threaded shaft 318can engage the threads of the second bore 332 of the second member 304.

The at least one pin 400 can comprise a plurality of pins. In oneaspect, at least one pin of the plurality of pins can be coupled to orformed integrally with the first member 302 and/or the second member 304of the insert. In another aspect, the distal end 404 of the at least onepin can be securedly attached to or formed integrally with thelongitudinal sidewall 314, 330 of the respective first member and/orsecond member. The proximal end 402 of the pin can extend away from thelongitudinal sidewall and be configured to engage at least one slot 148,248 defined in at least one of respective first plate 100 and the secondplate 200. In another aspect, at least one pin can be positioned suchthat a longitudinal axis of the pin L₄ is substantially transverse tothe longitudinal axis of the insert L₃.

With reference now to FIG. 13, the at least one slot 148 can be definedin the longitudinal sidewall 130 of the first plate 100 along a slotaxis L₅. In one aspect, the at least one slot of the first plate cancomprise a plurality of slots, such as, for example and withoutlimitation, a third slot 150 and a fourth slot 152. Each slot can have aleading end 154 and a trailing end 156, the leading end being positionedclosed to the upper bone contact surface 110 of the first plate than thetrailing end. In another aspect, the third slot and/or the fourth slotcan be positioned along the slot axis L₅ that is substantiallytransverse to the longitudinal axis L₁ of the first plate 100.Optionally, however, the slot axis L₅ of the third slot 150 and/or thefourth slot 152 can be at an acute slot angle relative to thelongitudinal axis L₁ of the first plate. In another aspect, the thirdslot and/or the fourth slot can be substantially parallel to each other.The third slot 150 can be sized, shaped and positioned to engage theproximal end 402 of a pin 400 coupled to the first member 302, and thefourth slot can be sized, shaped and positioned to engage the proximalend of a pin coupled to the second member 304.

Similarly, at least one slot 248 can be defined in the longitudinalsidewall 230 of the second plate 200. In one aspect, the at least oneslot of the second plate can comprise a fifth slot 250 and a sixth slot252. Each slot of the at least one slot can have a leading end 254 and atrailing end 256, the leading end being positioned closed to the lowerbone contact surface 210 than the trailing end. In another aspect, thefifth slot and/or the sixth slot can be positioned along the slot axisL₅ that is substantially transverse to the longitudinal axis L₂ of thesecond plate 200. Optionally, however, the slot axis of the fifth slot250 and/or the sixth slot 252 can be at an acute slot angle relative tothe longitudinal axis L₂ of the second plate. In another aspect, thefifth slot and/or the sixth slot can be substantially parallel to eachother. The fifth slot 250 can be sized, shaped and positioned to engagethe proximal end 402 of a pin 400 coupled to the first member 302, andthe sixth slot can be sized, shaped and positioned to engage theproximal end of a pin coupled to the second member 304.

To assemble the inter-body fusion device 10 according to thisembodiment, the insert 300 can be positioned between the first plate 100and the second plate 200 such that the leading edge 306 of the insert,the leading edge 102 of the first plate, and the leading edge 202 of thesecond plate are facing the same direction. In one aspect, portions ofthe first plate 100 can overlie the second plate 200. Correspondingly,in one aspect, each longitudinal sidewall 130 of the first plate 100 cansubstantially align with a longitudinal sidewall 230 of the second plate200. For example, each longitudinal sidewall of the first plate cansubstantially overlie at least a portion of a longitudinal sidewall ofthe second plate. Optionally, each longitudinal sidewall 130 of thefirst plate 100 can be positioned adjacent to at least a portion of alongitudinal sidewall 230 of the second plate 200 so that at least aportion of the inner surface 120 of the first plate and the innersurface 220 of the second plate can contact each other.

The proximal end 402 of a pin 400 can be coupled to the longitudinalsidewall 130 of the first plate 100 adjacent to the trailing edge 104,and the proximal end of a pin can be coupled to the longitudinalsidewall 230 of the second plate 200 adjacent to the trailing edge 204so that the distal end 404 of each pin can extend into the second slot342 of the second retainer 338 of the insert 300. Thus, when assembled,a portion of pin can slide in the second slot and allow the first plate100, the second plate 200, and/or the insert to move relative to eachother.

In one aspect, the distal end 404 of at least one pin 400 can be coupledto the longitudinal sidewall 314 of the first member 302, and the distalend of at least one pin can be coupled to the longitudinal sidewall 330of the second member so that the proximal end 402 of each pin can extendinto a respective slot (such as the third slot 150 and the fourth slot152 of the first plate 100, and the fifth slot 250 and the sixth slot252 of the second plate 200). Thus, when assembled, a portion of eachpin can slide in a slot and allow the first plate, the second plate,and/or the insert 300 to move relative to each other

When assembled, the device is adjustable about and between a firstunexpanded position and a second expanded position. In the firstunexpanded position, as illustrated in FIG. 13, a portion of the innersurface 120 of the first plate 100 and the inner surface 220 of thesecond plate 200 can contact each other and/or, a portion of a pin cancontact the leading end 154, 254 of each respective slot 148, 248. Inthe first unexpanded position, each of the first member 302 and thesecond member 304 of the insert 300 can be positioned substantiallywithin the interior cavity 15 formed between the substantially alignedlongitudinal sidewalls 130, 230 of the first and second plates 100, 200.In the second expanded position, as illustrated in FIG. 15, a portion ofthe inner surface 120 of the first plate 100 and the inner surface 220of the second plate 200 can be spaced from each other a predetermineddistance and/or, a portion of a pin can contact the trailing end 156,256 of each respective slot 148, 248. In the second expanded position,each of the first member 302 and the second member 304 of the insert 300can be positioned substantially within the interior cavity 15 formedbetween the substantially aligned longitudinal sidewalls 130, 230 of thefirst and second plates 100, 200. As can be appreciated, in the secondexpanded position, the inter-body fusion device 10 can have a height andinterior cavity 15 volume that is greater than the height and interiorcavity volume of the inter-body fusion device in the first, unexpandedposition. Thus, in the first unexpanded position, the interior cavity 15of the device can have a first cavity size, and in the second expandedposition the interior cavity has a second cavity size that is greaterthan the first cavity size.

In one aspect, in the first, unexpanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other. Inanother aspect, in the second, expanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other.

In order to selectively expand the inter-body fusion device 10 of FIGS.13-20 about and between the first unexpanded position and the secondexpanded position, at least the one of first member 302 or the secondmember 304 of the insert 300 can be moved longitudinally about andbetween a first insert position and a second insert position. In oneaspect, in the first insert position, the trailing edge 308 of the firstmember can be spaced from the trailing edge 104 of the first plate 100an unexpanded first distance and the trailing edge 324 of the secondmember can be spaced from the trailing edge 104 of the first plate 100an unexpanded second distance. In another aspect, in the second insertposition, the trailing edge 308 of the first member can be spaced fromthe trailing edge 104 of the first plate 100 an expanded first distancethat is less than the unexpanded first distance, and the trailing edge324 of the second member can be spaced from the trailing edge 104 of thefirst plate an expanded second distance that is less than the unexpandedsecond distance.

When adjusting the inter-body fusion device 10 of this embodiment aboutand between the first unexpanded position and the second expandedposition, the first member 302 and the second member 304 of the insert300 do not necessarily need be moved simultaneously or to the sameinsert position. For example, the first member can be in the firstinsert position while the second member can be in the second insertposition. In another example, the first member 302 can be in the secondinsert position while the second member 304 can be in the first insertposition. Thus, the first member and the second member can be in anyinsert position between the first insert position and the second insertposition at any time regardless of the position of the other member.

Upon moving the first member 302 towards the second insert position, atleast a portion of the at least one pin 400 coupled to or formedintegrally with the first member can be moved into contact with a wallof the third slot 150 in the first plate 100 and/or the fifth slot 250in the second plate. The pin can slide therein the slot from the leadingend 154, 254 of the slot towards the trailing end 156, 256 of therespective slot. If the slot is at an angle relative to the longitudinalaxis L.sub.1 of the first plate 100, then, the inclined wall of the slotcan urge the first plate and/or the second plate 200 away from eachother. For example, if the slot angle is an acute angle or a rightangle, the pin sliding in the slot can urge the first plate 100 and/orthe second plate 200 away from each other in the direction of the slot.

Similarly, upon moving the second member 304 towards the second insertposition, at least a portion of the at least one pin 400 coupled to orformed integrally with the second member can be moved into contact witha wall of the fourth slot 152 of the first plate 100 and/or the sixthslot 252 of the second plate. The pin can slide therein the slot fromthe leading end 154, 254 of the slot towards the trailing end 156, 256.If the respective slot is at an angle relative to the longitudinal axisL₁ of the first plate 100, then, the inclined wall of the slot can urgethe first plate and/or the second plate 200 away from each other.

In use, the second member driver 504 can be coupled to the distal end337 of the second member 304. If the device is in the first, unexpandedposition, rotation of the handle 506 can cause the first member 302 andthe second member 304 of the insert to move from the first insertposition towards the second insert position (that is, rotation of thehandle can cause the first member and the second member a to movelongitudinally toward the trailing edge 104 of the first plate 100),thereby urging the first plate and second plate away from each other.Upon reaching the desired device height, the second member driver can beremoved from the second member 304, and a separate first member driver502 can be inserted through the longitudinal duct 339 of the secondthreaded shaft 336 of the second member and through the longitudinalpathway 334 of the second member so that the first member driver can becoupled to the distal end 319 of the first threaded shaft 318 of thefirst member 302. Rotation of the first member driver can cause thefirst member to move longitudinally, thereby changing the angle betweenthe first plate and the second plate (the device angle). For example,rotation of the first member driver in a first direction can cause thefirst member 302 to move longitudinally towards the trailing edge 104 ofthe first plate, thereby increasing the device angle. In anotherexample, rotation of the first member driver 502 in a second directionthat is opposed to the first direction can cause the first member 302 tomove longitudinally towards the leading edge 102 of the first plate 100,thereby decreasing the device angle. When the desired device angle hasbeen reached, the first member driver can be removed from the device 10.

A third embodiment of the inter-body fusion device 10 is illustrated inFIGS. 21-28, according to one aspect. In this embodiment, the inter-bodyfusion device can be as described above, comprising a first plate 100, asecond plate 200, and an insert 300. Optionally, however, the insert canbe a coupled to a portion of the second plate.

The second plate 200 of this embodiment comprise a mounting surface 258and at least one sleeve 260 having an internal sleeve diameter fixedlyattached thereto. Each sleeve can be configured to couple a portion ofthe insert to the second plate. For example, a first sleeve 262 can beattached to the mounting surface so that a portion on the second member304 of the insert can slide through the first sleeve. That is, the firstsleeve can act as a bushing to maintain the longitudinal axis L3 of theinsert in substantial alignment with the longitudinal axis L₂ of thesecond plate as the second member 304 of the insert moves longitudinallyrelative to the second plate 200. In another aspect, a second sleeve 264can be positioned near or adjacent to the trailing edge 204 of thesecond plate and can act similar to the second retainer 238 to couple aportion of the second member 304 to the second plate 200. At least onepin bore 266 can be defined therein a portion of a longitudinal sidewall268 of the first and/or second sleeve. In a further aspect, alongitudinal groove 272 can be defined in the mounting surface 258, thelongitudinal groove sized and shaped so that a portion of an outersurface 301 of the first member 302 and/or the second member 304 canslide therein. The shoulder 346 of the second threaded shaft can engagea portion of the second sleeve 264 and/or the second plate 200 torestrict movement of the second threaded shaft longitudinally towardsthe leading edge 202 of the second plate.

Rotation of the second threaded shaft 336 can cause the distance betweenthe trailing edge 324 of the second member 304 and the second sleeve 264to change. For example, rotation of the second threaded shaft in a firstdirection can make the distance between the trailing edge of the secondmember and the second sleeve smaller. In another example, rotation ofthe second threaded shaft 336 in a second direction that is opposed tothe first direction can make the distance between the trailing edge 324of the second member 304 and the second sleeve 264 larger.

The at least one pin 400 can comprise a plurality of pins. In oneaspect, at least one pin of the plurality of pins can be coupled to orformed integrally with the first member 302 and/or the second member 304of the insert. In another aspect, the distal end 404 of the at least onepin can be securedly attached to or formed integrally with the outersurface 301 of the first member and/or the second member. In anotheraspect, at least one pin can be positioned on the first member 302and/or the second member 304 such that a longitudinal axis of the pinL.sub.4 is substantially transverse to the longitudinal axis L.sub.3 ofthe insert 300. The proximal end 402 of the pin can extend away from theouter surface and can be configured to engage at least one slot 148defined in the first plate 100.

With reference now to FIG. 21, the at least one slot 148 can be definedin the longitudinal sidewall 130 of the first plate 100, and the atleast one slot of the first plate can comprise the third slot 150 andthe fourth slot 152. In one aspect, a seventh slot 162 can be defined inthe longitudinal sidewall of the first plate near or adjacent to thetrailing edge 104 of the first plate 100. Each slot of the at least oneslot can have the leading end 154 and the trailing end 156, with theleading end being positioned closed to the upper bone contact surface110 of the first plate than the trailing end. In another aspect, thethird slot, the fourth slot and/or the seventh slot can be positionedalong the slot axis L₅ that is substantially transverse to thelongitudinal axis L₁ of the first plate 100. Optionally, however, theslot axis L₅ of the third slot 150, the fourth slot 152 and/or theseventh slot 162 can be at an acute slot angle relative to thelongitudinal axis L₁ of the first plate. In another aspect, the thirdslot, the fourth slot and/or the seventh slot can be substantiallyparallel to each other. The third slot 150 can be sized, shaped andpositioned to engage the proximal end 402 of a pin 400 coupled to thefirst member 302, and the fourth slot can be sized, shaped andpositioned to engage the proximal end of a pin coupled to the secondmember 304. The seventh slot 162 can be sized, shaped and positioned toengage the proximal end 402 of a pin 400 coupled to the second sleeve264.

To assemble the inter-body fusion device 10 according to thisembodiment, the insert 300 can be coupled to the second plate 200. Forexample, the leading edge 322 of the second member 304 can be insertedthrough the first sleeve 262, and the first threaded shaft 318 of thefirst member 302 can complementarily engage a portion of the threads ofthe second bore 332 of the second member 304. A portion of the secondthreaded shaft 336 can be inserted through the second sleeve 264 and thesecond threaded shaft can complementarily engage a portion of thethreads of the second bore 332.

The distal end 404 of at least one pin 400 can be coupled to the pinbore 266 of the second sleeve 264 so that the proximal end 402 of eachpin can extend into the seventh slot 162 of the first plate. Thus, whenassembled, a portion of the pin can slide in the seventh slot and allowthe first plate 100 and the second plate 200 to move relative to eachother. In one aspect, the distal end 404 of at least one pin 400 can becoupled to the outer surface 301 of the first member 302 and/or thedistal end of at least one pin can be coupled to the outer surface ofthe second member 304 so that the proximal end 402 of each pin canextend into a slot, such as the third slot 150 and the fourth slot 152of the first plate 100. Thus, when assembled, a portion of each pin canslide in a slot and allow the first plate to move relative to the secondplate.

When assembled, the inter-body fusion device 10 is adjustable about andbetween a first unexpanded position and a second expanded position. Inthe first unexpanded position, as illustrated in FIG. 23, a portion ofthe inner surface 120 of the first plate 100 and the inner surface 220of the second plate 200 can contact each other and/or, a portion of apin 400 can contact the leading end 154 of a slot 148. In the firstunexpanded position, each of the first member 302 and the second member304 of the insert 300 can be positioned substantially within theinterior cavity 15 formed between the substantially aligned longitudinalsidewalls 130, 230 of the first and second plates 100, 200. In thesecond expanded position, as illustrated in FIG. 21, a portion of theinner surface 120 of the first plate 100 and the inner surface 220 ofthe second plate 200 can be spaced from each other a predetermineddistance and/or, a portion of a pin can contact the trailing end 156 ofa slot 148. In the second expanded position, each of the first member302 and the second member 304 of the insert 300 can be positionedsubstantially within the interior cavity 15 formed between thesubstantially aligned longitudinal sidewalls 130, 230 of the first andsecond plates 100, 200. As can be appreciated, in the second expandedposition, the inter-body fusion device 10 can have a height and interiorcavity 15 volume that is greater than the height and interior cavityvolume of the inter-body fusion device in the first, unexpandedposition. Thus, in the first unexpanded position, the interior cavity 15of the device can have a first cavity size, and in the second expandedposition the interior cavity has a second cavity size that is greaterthan the first cavity size.

In one aspect, in the first, unexpanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other. Inanother aspect, in the second, expanded position, the longitudinal axisL₁ of the first plate 100 and the longitudinal axis L₂ of the secondplate 200 can be substantially parallel to each other or, optionally,the longitudinal axis L₁ of the first plate and the longitudinal axis L₂of the second plate can be at an acute angle relative to each other.

In order to selectively expand the inter-body fusion device 10 of FIGS.21-28 about and between the first unexpanded position and the secondexpanded position, at least the one of first member 302 or the secondmember 304 of the insert 300 can be moved longitudinally about andbetween a first insert position and a second insert position. In oneaspect, in the first insert position, the trailing edge 308 of the firstmember can be spaced from the trailing edge 204 of the second plate 200an unexpanded first distance and the trailing edge 324 of the secondmember can be spaced from the trailing edge 204 of the second plate anunexpanded second distance. In another aspect, in the second insertposition, the trailing edge 308 of the first member can be spaced fromthe trailing edge 204 of the second plate 200 an expanded first distancethat is less than the unexpanded first distance, and the trailing edge324 of the second member can be spaced from the trailing edge 204 of thesecond plate an expanded second distance that is less than theunexpanded second distance.

When adjusting the inter-body fusion device 10 of this embodiment aboutand between the first unexpanded position and the second expandedposition, the first member 302 and the second member 304 of the insert300 do not necessarily need be moved simultaneously or to the sameinsert position. For example, the first member can be in the firstinsert position while the second member can be in the second insertposition. In another example, the first member 302 can be in the secondinsert position while the second member 304 can be in the first insertposition. Thus, the first member and the second member can be in anyinsert position between the first insert position and the second insertposition at any time regardless of the position of the other member.

Upon moving the first member 302 towards the second insert position, atleast a portion of the at least one pin 400 coupled to or formedintegrally with the first member can be moved into contact with a wallof the third slot 150 in the first plate 100. The pin can slide thereinthe slot from the leading end 154 of the slot towards the trailing end156 of the slot. If the slot is at an angle relative to the longitudinalaxis L₁ of the first plate 100, then, the inclined wall of the slot canurge the first plate away from the second plate. For example, if theslot angle is an acute angle or a right angle, the pin sliding in theslot can urge the first plate 100 away from the second plate in thedirection of the slot.

Similarly, upon moving the second member 304 towards the second insertposition, at least a portion of the at least one pin 400 coupled to orformed integrally with the outer surface 301 of the second member can bemoved into contact with a wall of the fourth slot 152 of the first plate100. The pin can slide therein the slot from the leading end 154 of theslot towards the trailing end 156. If the respective slot is at an anglerelative to the longitudinal axis L₁ of the first plate 100, then, theinclined wall of the slot can urge the first plate away from the secondplate 200.

In use, the second member driver 504 can be coupled to the distal end337 of the second member 304. If the device is in the first, unexpandedposition, rotation of the handle 506 can cause the first member 302 andthe second member 304 of the insert to move from the first insertposition towards the second insert position (that is, rotation of thehandle can cause the first member and the second member to movelongitudinally toward the trailing edge 104 of the first plate 100). Asthe first and second members move longitudinally, the pin 400 coupled tothe first member engages the third slot 150 and the pin coupled to thesecond member engages the fourth slot 152. The angle of the slotsrelative to the longitudinal axis L.sub.2 of the second plate can causethe pin to urge the first plate in the slot direction thereby urging thefirst plate 100 away from the second plate.

Upon reaching the desired device height, the second member driver can beremoved from the second member 304, and the first member driver 502 canbe inserted through the longitudinal duct 339 of the second threadedshaft 336 of the second member and through the longitudinal pathway 334of the second member so that the first member driver can be coupled tothe distal end 319 of the first threaded shaft 318 of the first member.Rotation of the first member driver can cause the first member to movelongitudinally so that the pin 400 coupled to the first member engagesthe third slot 150, and the angle of the slot relative to thelongitudinal axis L₂ of the second plate can cause the pin to urge thefirst plate in the slot direction. Thus, this changes the angle betweenthe first plate and the second plate (the device angle). For example,rotation of the first member driver in a first direction can cause thefirst member 302 to move longitudinally towards the trailing edge 104 ofthe first plate, thereby increasing the device angle. In anotherexample, rotation of the first member driver 502 in a second directionthat is opposed to the first direction can cause the first member 302 tomove longitudinally towards the leading edge 102 of the first plate 100,thereby decreasing the device angle. When the desired device angle hasbeen reached, the first member driver can be removed from the device 10.

Also presented herein are methods of using an inter-body fusion device10 during an inter-body fusion procedure. In one aspect, the methodcomprises accessing the desired disc space, choosing the inter-bodyfusion device size with the appropriate height, inserting the inter-bodyfusion device 10 into the desired area in the disc space, expanding theinter-body fusion device from the first unexpanded position to thesecond expanded position with longitudinal movement of the insert 300,and adjusting the angle of the of the first plate 100 relative to thesecond plate. An additional step of packing the interior cavity 15 viathe longitudinal duct 339 of the second threaded shaft 336 and thelongitudinal pathway 334 of the second member 304 with bone fusionmaterial after expansion is also contemplated. In one aspect, the methodof using an inter-body fusion device 10 during an inter-body fusionprocedure further comprises the step of securing the insert to the firstand second plates. In another aspect, the method of using an inter-bodyfusion device during an inter-body fusion procedure further comprisesthe step of securing the inter-body fusion device 10 to the surroundingbony structure.

In one aspect, the step of choosing the inter-body fusion device 10 sizewith the appropriate height and angle comprises placing an undersizedtrial device in the disc space, expanding the trial device to the secondexpanded position, and repeating until the correct height and lordosisis found. The trial height and angle gives the information to prescribethe correct inter-body fusion device for the procedure.

Although several aspects of the invention have been disclosed in theforegoing specification, it is understood by those skilled in the artthat many modifications and other aspects of the invention will come tomind to which the invention pertains, having the benefit of the teachingpresented in the foregoing description and associated drawings. It isthus understood that the invention is not limited to the specificaspects disclosed hereinabove, and that many modifications and otheraspects are intended to be included within the scope of the appendedclaims. Moreover, although specific terms are employed herein, as wellas in the claims that follow, they are used only in a generic anddescriptive sense, and not for the purposes of limiting the describedinvention.

What is claimed is:
 1. An inter-body fusion device for use in surgerycomprising: a first plate having a leading edge, a trailing edge, anupper bone contact surface, an opposed first plate inner surface, and afirst plate longitudinal axis; a second plate having a leading edge, atrailing edge, a lower bone contact surface, an opposed second plateinner surface, and a second plate longitudinal axis, wherein the firstplate substantially overlies the second plate and is positioned suchthat the first plate longitudinal axis and the second plate longitudinalaxis together form a device angle therebetween; and an insert comprisinga first member having a leading edge, a trailing edge, an upper platecontact surface and an opposed lower plate contact surface, and a secondmember having a leading edge, a trailing edge, an upper plate contactsurface and an opposed lower plate contact surface, the insertpositioned substantially between the first plate and the second plate,wherein movement of the first member longitudinally with respect to thefirst and second plates increases a distance between a portion of theleading edge of the first and second plates and movement of the secondmember longitudinally with respect to the first and second platesincreases a distance between a portion of the trailing edge of the firstand second plates, and wherein the first and second members of theinsert are separate and operate independently such that when engaged bya device driver the first member and second member move longitudinallyindependently, enabling a user to selectively alter both the distancebetween the first plate and the second plate and the device angle,wherein portions of the first member of the insert are positioned andconfigured to act on an inclined surface of the first plate and aninclined surface of the second plate to facilitate expanding theinter-body fusion device by selectively separating portions of theleading edges of the first and second plates and wherein portions of thesecond member of the insert are positioned and configured to act on aninclined surface of the first plate and an inclined surface of thesecond plate to facilitate expanding the inter-body fusion device byselectively separating the trailing edges of the first and secondplates.
 2. The inter-body fusion device of claim 1, wherein the deviceangle is 0 degrees such that the first plate and the second plate aresubstantially parallel to each other.
 3. The inter-body fusion device ofclaim 1, wherein the device angle is an acute angle between 1 degree and45 degrees.
 4. The inter-body fusion device of claim 1, wherein thedevice angle is an acute angle between 5 degrees and 30 degrees.
 5. Theinter-body fusion device of claim 1, wherein the device angle is anacute angle between 10 degrees and 20 degrees.
 6. The inter-body fusiondevice of claim 1, wherein the first plate further comprises a pair oflongitudinal sidewalls extending from a portion of the first plate innersurface, wherein the second plate further comprises a pair oflongitudinal sidewalls extending from a portion of the second plateinner surface, and wherein one of the pairs of longitudinal sidewalls ispositioned adjacent the other pair of longitudinal sidewalls.
 7. Theinter-body fusion device of claim 6, wherein the longitudinal sidewallof the first plate defines a first inclined slot and a second inclinedslot, each inclined slot having a leading end and a trailing end, andeach leading end being positioned closer to the leading edge of thefirst plate.
 8. The inter-body fusion device of claim 7, wherein thefirst inclined slot is defined along a first slot axis which ispositioned at an acute angle relative to the longitudinal axis of thefirst plate, and wherein the second inclined slot is defined along asecond slot axis which is positioned at an acute angle relative to thefirst plate longitudinal axis.
 9. The inter-body fusion device of claim8, wherein the first slot axis and the second slot axis are parallel toone another.
 10. The inter-body fusion device of claim 8, wherein thefirst slot axis and the second slot axis are substantially transverse tothe first plate longitudinal axis.
 11. The inter-body fusion device ofclaim 7, wherein at least one of the longitudinal sidewalls of thesecond plate defines a third inclined slot and a fourth inclined slot,each inclined slot having a leading end and a trailing end.
 12. Theinter-body fusion device of claim 11, wherein the third inclined slot isdefined along a third slot axis which is positioned at an acute anglerelative to the second plate longitudinal axis, and wherein the fourthinclined slot is defined along a fourth slot axis which is positioned atan acute angle relative to the second plate longitudinal axis.
 13. Theinter-body fusion device of claim 12, wherein the third slot axis andthe fourth slot axis are parallel to one another.
 14. The inter-bodyfusion device of claim 12, wherein the third slot axis and the fourthslot axis are substantially transverse to the first plate longitudinalaxis.
 15. The inter-body fusion device of claim 1, wherein the firstmember of the insert is spaced from the second member of the insert. 16.The inter-body fusion device of claim 1, wherein the trailing edge ofthe first member of the insert defines a first bore configured to engagea threaded shaft, wherein rotation of the threaded shaft in a firstdirection moves the first member of the insert proximally and rotationof the threaded shaft in a second direction moves the first member ofthe insert distally.
 17. The inter-body fusion device of claim 16,wherein the second member of the insert defines a second bore thatextends longitudinally through the second member, the second boreconfigured to engage a second threaded shaft, wherein rotation of thesecond threaded shaft in a first direction moves the second member ofthe insert proximally and rotation of the second threaded shaft in asecond direction moves the second member of the insert distally.
 18. Theinter-body fusion device of claim 17, wherein a distal end of the secondthreaded shaft defines a feature configured to engage an actuationdevice, such that rotation of the actuation device can rotate the secondthreaded shaft.
 19. The inter-body fusion device of claim 18, wherein alongitudinal duct is defined through the second threaded shaft and isconfigured to enable at least a portion of the actuation device to beinserted through the longitudinal duct.
 20. An inter-body fusion devicefor use in surgery comprising: a first plate having a leading edge, atrailing edge, an upper bone contact surface, an opposed first plateinner surface, and a first plate longitudinal axis; a second platehaving a leading edge, a trailing edge, a lower bone contact surface, anopposed second plate inner surface, and a second plate longitudinalaxis, wherein the first plate substantially overlies the second plateand is positioned such that the first plate longitudinal axis and thesecond plate longitudinal axis together form a device angletherebetween; an insert comprising a first member having a leading edge,a trailing edge, an upper plate contact surface and an opposed lowerplate contact surface, and a second member having a leading edge, atrailing edge, an upper plate contact surface and an opposed lower platecontact surface, the insert positioned substantially between the firstplate and the second plate, wherein the second member is spaced from thefirst member, wherein the second member is configured to allow access toa device driver that is configured to move a portion of the firstmember, wherein movement of the first member longitudinally with respectto the first and second plates increases a distance between the leadingedge of the first and second plates and movement of the second memberlongitudinally with respect to the first and second plates increases thedistance between the trailing edge of the first and second plates, andwherein the first and second members of the insert operate independentlysuch that when engaged by a device driver the first member and secondmember move longitudinally independently, enabling a user to selectivelyalter both the distance between the first plate and the second plate andthe device angle, wherein portions of the first member of the insert arepositioned and configured to act on an inclined surface of the firstplate and an inclined surface of the second plate to facilitateexpanding the inter-body fusion device by selectively separatingportions of the leading edges of the first and second plates and whereinportions of the second member of the insert are positioned andconfigured to act on an inclined surface of the first plate and aninclined surface of the second plate to facilitate expanding theinter-body fusion device by selectively separating the trailing edges ofthe first and second plates; and wherein the trailing edge of the firstmember of the insert defines a first bore configured to engage athreaded shaft, wherein rotation of the threaded shaft in a firstdirection moves the first member of the insert proximally and rotationof the threaded shaft in a second direction moves the first member ofthe insert distally and wherein the second member of the insert definesa second bore that extends longitudinally through the second member, thesecond bore configured to engage a second threaded shaft, whereinrotation of the second threaded shaft in a first direction moves thesecond member of the insert proximally and rotation of the secondthreaded shaft in a second direction moves the second member of theinsert distally.
 21. The inter-body fusion device of claim 20, wherein adistal end of the second threaded shaft defines a feature configured toengage an actuation device, such that rotation of the actuation devicecan rotate the second threaded shaft.
 22. The inter-body fusion deviceof claim 21, wherein a longitudinal duct is defined through the secondthreaded shaft configured to enable at least a portion of the actuationdevice to be inserted through the longitudinal duct.
 23. A method ofusing an inter-body fusion device during an inter-body fusion procedurecomprising: accessing a desired disc space; choosing an inter-bodyfusion device size with an appropriate height, the inter-body fusiondevice comprising: a first plate having a leading edge, a trailing edge,an upper bone contact surface, an opposed first plate inner surface, anda first plate longitudinal axis; a second plate having a leading edge, atrailing edge, a lower bone contact surface, an opposed second plateinner surface, and a second plate longitudinal axis, wherein the firstplate substantially overlies the second plate and is positioned suchthat the first plate longitudinal axis and the second plate longitudinalaxis together form a device angle therebetween; and an insert comprisinga first member having a leading edge, a trailing edge, an upper platecontact surface and an opposed lower plate contact surface, and a secondmember having a leading edge, a trailing edge, an upper plate contactsurface and an opposed lower plate contact surface, the insertpositioned substantially between the first plate and the second plate,wherein the first and second members operate independently such thatwhen engaged by a device driver the first member and second member movelongitudinally independently, to enable a user to selectively alter botha distance between the first plate and the second plate and the deviceangle; inserting the inter-body fusion device into the desired discspace; expanding the inter-body fusion device from a first unexpandedposition to a second expanded position, wherein expanding the inter-bodyfusion device comprises moving the first member longitudinally withrespect to the first and second plates, increasing the distance betweenan inclined surface of the first and second plates, and moving of thesecond member longitudinally with respect to the first and secondplates, increasing the distance between the trailing edge of the firstand second plates; and adjusting the angle of the first plate relativeto the second plate.